1. Field of the Invention
The present invention relates to a luminous display device for electric equipments of the type comprising a base container, within which a light source is disposed and on top of which a board carrying silk-screen printed alphanumeric characters is positioned which is slightly translucent at the lower part thereof.
2. Prior Art
It is known that all electric equipments are provided with a control board for the display and programming of the functions accomplished by each individual machine. It is in fact important to be able to inform the user about the operating state of the equipment, by indicating the noteworthy parameters of each function in a precise manner at the moment that said function is being accomplished (program, time, temperature, etc.).
This type of requirement has been mainly felt in the field of household users where control and indication boards are normally applied to the various equipments, such as for example washing machines, dishwashers, etc.
Up to now warning lights consisting of lamps sometimes of different colours have been mainly used.
In greater detail the operating indications of an equipment are accomplished by means of lamps that, being lighted by turns depending upon requirements, highlight a respective character or symbolism under which they are positioned. It is therefore apparent that it is necessary to use as many lamps as the required characters and that in case of long symbolisms, such as indication words or the like, the number of lamps needed would be so high that their use has not been considered advisable until now.
On the other hand it is to be pointed out that it is important to be able to identify the operating step of an equipment in a quick and precise manner.
However, at the present state of the art, as above said, it is not possible to carry out the display of expressions, numbers and symbolisms normally present on the control boards of equipments in a simple and quick manner as regards circuits and construction, by means of a cheap engineering technique.
In fact electronic displays also involving the use of liquid crystals need an appropriate input signal and the display of a complicated and relatively expensive electronic decoder.